Across many measures, immigrant and refugee populations arrive to the US healthier than the general population, but the longer they reside in the US, the more they approximate the cardiovascular risk profiles of the general population. These declines are mediated, in part, by less physical activity and lower dietary quality upon immigration among both adults and their children. Given the complex socio-cultural forces that influence these behaviors, a community-based participatory research (CBPR) approach is called for to address them. The Rochester Healthy Community Partnership is a robust CBPR partnership in Rochester, Minnesota consisting of community-based organizations, health service organizations, and academics who are experienced at collectively deploying programming and outcomes assessment among immigrant and refugee populations. Community and academic partners have shared the responsibility of preparing this project. The specific aims are: 1) To develop a sustainable, socio-culturally appropriate physical activity and nutrition intervention with and for immigrant and refugee families, and 2) to evaluate the efficacy of the physical activity and nutrition intervention. The intervention framework is a series of home-based, individualized family mentoring and education session for physical activity and nutrition led by trained Family Health Promoters from each of the participating immigrant and refugee communities (Hispanic, Somali, Sudanese, Cambodian) with opportunities for group activities. Using a two-group randomized design, 160 individuals (including both adults and adolescents) will be randomly assigned to receive the intervention either immediately or after a delay of one year. Primary outcomes assessed in both adults and adolescents, measured up to two years after implementation, will include physical activity as measured by accelerometry and dietary change as measured by 24 hour dietary recalls. Secondary outcomes will include changes in body mass index, body composition, blood pressure, waist-hip ratio, and health-related quality of life. Innovative approaches that arise organically from the affected communities are needed to create and sustain interventions that promote healthy behaviors. The use of CBPR will enhance the relevance of this program by targeting socio-cultural determinants of physical activity and nutrition.